Question

Julia is taking a test with multiple choice and true/false question the test has twentg question altogether . julia gets five points for correct multiple choice answer nd lose one points for each incorrect true/fales answers . she earned 76 points in the test how many multilpe choice question and true/fales question are one the test ? .
let ___ =________
let ___=________
system of equestion :




solution :

plzz help fastt :)

Answer 1

X=number of corect
y=number of incorrect
5 points for each correct so 5x
-1 point for each incorrect so -y

5x-y=76
solve for x and y

I like putting it into slope intercep tofrm which is y=mx+b
add y to both sides
5x=76+y
subtract 76 from both sides
5x-75=y
y=5x-76

subsitute values for x and get values for y
remember, that julia cannot answer a negative number of incorrect questions so y must be greater than or equal to 0

so solve for minimum
0<5x-76
add 76 to both sides
76<5x
divide by 5
15.2<x
you cannot answer a fraction of a correct quesiton so round up
16 is the minumum number of queswtions correctlyh answered


so
x>16

subsitute 16 for x
y=5(16)-76
y=80-76
y=4

as we subsitute more numbers over 16, we get these points
so (x,y) 
(16,4)
(17,9)
(18,14)
(19,19)
(20,24)
(21,29)
(22,34)
(23,39)
x=correct answer
y=wrong answers